Numerous types of fastening devices with tolerance compensation are known. Typically, these devices comprise an adjusting bushing with a so-called “carrying section” or “dragging section”, which can enter into a friction-locked connection to a fastening screw. When the fastening screw is rotated, the adjusting bushing is then rotated along with it, until the bushing abuts against one of the two components which are disposed a distance apart. When the fastening screw is further rotated, with corresponding increasing of the torque, the friction-locked connection between the fastening screw and the carrying or dragging section is overcome, so that then the two components can be forcibly held together by the fastening screw, via the adjusting bushing.
EP 1666342 B1 describes such a fastening device, with a carrying or dragging section disposed on the fastening screw. In particular, the carrying section is comprised of a deformed thread region which cannot be screwed into the inner thread of the compensating element. Therefore, the compensating element is first rotated along with the fastening screw, by the fastening screw. Only when the compensating element abuts against a component, a blocked torque can be overcome, so that the deformed thread region enters into the thread of the compensating element. In addition to the carrying or dragging element itself, the tolerance compensating element has a space-consuming design in both the radial and the axial direction, so that a correspondingly large space in the installation between the two components must be provided for.
EP 1260717 discloses a fastening device wherein the fastening screw also carries the compensating element along with it as it rotates. This co-rotation is brought about, e.g., in that the thread of the fastening screw is coated with a frictional agent or the like, so that an elevated torque is needed to screw the fastening screw into the thread of the compensating element. Thus, the compensating element is rotated along with the fastening screw, until the compensating element abuts against the opposing component.
In the fastening device of WO 2010/066363 A1, a compensating element is provided, the interior side of which is similar to that of a carrying bushing. This carrying bushing of plastic provides a friction-locked connection for the fastening screw, as a result of its reduced diameter compared to the outer diameter of the fastening screw. On this basis, the fastening screw rotates carrying the compensating element with it, until the compensating element abuts against the opposite component. This plastic bushing for carrying along the compensating element has an inner thread which is smaller than the outer thread of the fastening screw. Therefore, a higher torque is needed in order to screw the fastening screw into this plastic bushing, so that the fastening screw initially rotates carrying the compensating element along with it. This fastening device also requires a large accommodation space both in the radial and the axial direction, so that it is disadvantageous in a situation where economy of space is needed. Also, the fastening screw must fully pass through the plastic bushing during installation, which increases the time needed for installation of the fastening device, due to the increased torque. If the plastic bushing is dimensioned too short or too soft, the fastening screw may be passed through in a disadvantageous manner.
Based on the above-discussed state of the art, the underlying problem of the present invention is to provide a fastening device for fastening a component B to a component A with automatic tolerance compensation in the distance between the two components, which device requires small accommodating space and is installable at low cost compared to the state of the art.